G'Day Ed, On Wed, Oct 29, 2014 at 12:40 PM, Ed Maste <ema...@freebsd.org> wrote: > On 28 October 2014 13:38, Brendan Gregg <brendan.d.gr...@gmail.com> wrote: >> Ah, thanks, I'm on 10.0-STABLE and I have: >> >> kern.hwpmc.callchaindepth: 8 >> >> Glad it's something simple! > > Those are the best kinds of problems to have, although we ought to > make sure this point is covered in the FreeBSD profiling documentation > that we have or create.
Yes; at least we have this thread now, which should be searchable. > > Also, do you think that we should bump the compiled-in default up to 32? Yes. When I'm using profiling data, I like full stacks for making flame graphs. For the FreeBSD kernel, 32 frames should usually be enough (I have a flame graph that reaches 24 frames for the kernel, but no more). For user-level, I'd probably need ~100. So making the compiled-in default to 32 would hopefully be sufficient for most kernel profiling, and one would need to bump that up for deep user-level stacks. I guess this would also need PMC_CALLCHAIN_DEPTH_MAX = 128 to work. Brendan _______________________________________________ freebsd-performance@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-performance To unsubscribe, send any mail to "freebsd-performance-unsubscr...@freebsd.org"
